Why does the alleged onset date matter?
In both Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI) cases, the alleged onset date (AOD) is when a disability claimant became unable to work because of a severe physical or mental impairment. For both SSDI and SSI, claimants’ impairments must be expected to prevent them from working for at least twelve months or to result in their death.
The AOD is important because it determines when benefit payments begin and when a claimant’s past-due benefits (“back pay”) begins accumulating.
In an SSI disability case, benefits are payable in the month after the AOD or the month after the claimant filed an application, whichever is later. Because benefits are not payable until the month after the SSI disability claimant files, it is important to file an SSI application as soon as a claimant becomes unable to work.
In an SSDI disability case, benefits are first payable six months after the AOD and up to one year before the claimant filed the disability application. Because benefits are only payable for up to a year before the SSDI disability application is filed and because it can prove difficult to prove a case once the date last insured (DLI) has expired, it is important to file an SSDI application as soon as the claimant becomes unable to work.
If you need help filing an application for SSDI or SSI disability benefits because of a severe illness or injury, you should contact an experienced disability lawyer for help and advice proving your case.